The Risk of Anal Carcinoma After Anogenital Warts in Adults Living With HIV
Justin D. Arnold, Morgan Byrne, Anne K. Monroe, Stephen Abbott
Abstract
Importance: In the US, incidence of and mortality due to anal carcinoma are rising faster than for most other cancers. Identifying populations who have a higher risk of developing anal cancers is critical to target preventive interventions. Objective: To assess the risk of developing anal carcinoma in adults living with HIV who have a history of anogenital warts. Design, Setting, and Participants: This longitudinal cohort study included adults living with HIV from 14 clinics in Washington, DC, and at least 18 months of follow-up. Data were collected from January 1, 2011, to March 31, 2017, and analyzed from June 1, 2019, to October 31, 2020. Exposures: Development of warts in the anal or genital region identified by diagnosis codes. Main Outcomes and Measures: Individuals with anal carcinoma were identified by diagnosis codes or anal biopsy results. Results: A total of 6515 participants were enrolled (4720 male [72.4%] at birth; mean [SD] age, 49.9 [12.7] years), and 383 (5.9%) developed anogenital warts during the study period. Patients who were diagnosed with anogenital warts were more likely to subsequently develop anal carcinoma (17 of 383 [4.4%]) compared with participants without a history of anogenital warts (17 of 6132 [0.3%]) (P < .001). After adjusting for covariates, the odds of developing anal carcinoma were 12.79 (95% CI, 6.19-26.45; P < .001) times higher in individuals with a history of anogenital warts compared with individuals without a history of anogenital warts. Conclusions and Relevance: These findings suggest that adults living with HIV who have a history of anogenital warts have a substantially increased risk of developing anal carcinoma. Clinicians should counsel individuals living with HIV who have anogenital warts on this risk.